# Copyright 2023 Huawei Technologies Co., Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from .rotary_embeddings import RotaryEmbedding  as FastRotaryEmbedding, rotate_half
import torch.nn.functional as F


def apply_rotary_pos_emb_index_bhs(q, k, cos, sin, position_id):
    """
    位置编码计算
    """
    # batch_size, num_head, seq_len, hidden_size
    cos, sin = F.embedding(position_id, cos.squeeze(1)).unsqueeze(1), \
               F.embedding(position_id, sin.squeeze(1)).unsqueeze(1)
    q = (q * cos) + (rotate_half(q) * sin)
    k = (k * cos) + (rotate_half(k) * sin)
    return q, k

